Automapper Not Mapping JObject To POCO Not Mapping Int - c#

Example code
JToken json = JObject.Parse(
" {\"Url\": \"www.fakeUrl.com\",\"CallId\": 12}");
var poco = mapper.Map<CallData>(json);
Console.WriteLine(json);
Console.WriteLine(poco.Url + " " + poco.CallId);
Simple Model
public class CallData
{
public int CallId { get; set; }
public string Url { get; set; }
}
Output
{ "Url": "www.fakeUrl.com", "CallId": 12 }
www.fakeUrl.com 0
I'm just curious to why Automapper isn't mapping the integer in this JSON object? I know there are alternatives out such as a custom extension for this but I'm wondering why AutoMapper can't do this simple map?
Automapper V7.0.1

I resolved the issue by adding a custom mapping. I still believe this to be an issue with the underlining libraries and will investigate further as this simple primitive mapping shouldn't need extensions.
Mapper
CreateMap<dynamic ,CallData>().ConvertUsing((jo) =>
{
var callData = new CallData();
JsonSerializer serializer = new JsonSerializer();
if(jo != null)
serializer.Populate((JsonReader) jo.CreateReader(), callData);
return callData;
});
Usage
var response =_mapper.Map<dynamic, CallData>(_callData);

Related

Deserialize JSON to a dynamic object or a class in C#

I am trying to deserialize JSON into an object so I can add it to elastic search. JSON can be of many different object types in the project so I would like the function to be dynamic.
First I am serializing the Data that I get from EF Core context
var serializedObject = JsonConvert.SerializeObject(document, Formatting.None,
new JsonSerializerSettings()
{
ReferenceLoopHandling = ReferenceLoopHandling.Ignore
});
Next I would like to deserialize to an object. For example if I have
public class EValues
{
public dynamic values { get; set; }
}
var test = JsonConvert.DeserializeObject<EValues>(serializedObject.ToString());
I would like the JSON to be deserialized to the below:
{
"values":{
"StudentId":"60712555-ff1d-4a3e-8c81-08d9c2fc4423",
"Student":{
"Name":"string",
"Country":"string",
"Street":"string"
}
}
}
The serializedObject JSON I am actually trying to deserialize:
{
"StudentId":"60712555-ff1d-4a3e-8c81-08d9c2fc4423",
"Student":{
"Name":"string",
"Country":"string",
"Street":"string"
}
}
You can just do:
var test = new EValues {
values = JsonConvert.DeserializeObject<dynamic>(serializedObject)
};
The JSON that would correspond to EValues would have an extra level of nesting { "values" : {} } not present in your serializedObject JSON.

System.Text.Json JsonSerializer.Deserialize ignortes PropertyNamingPolicy [duplicate]

I recently upgraded a solution to be all .NET Core 3 and I have a class that requires the class variables to be fields. This is a problem since the new System.Text.Json.JsonSerializer doesn't support serializing nor deserializing fields but only handles properties instead.
Is there any way to ensure that the two final classes in the example below have the same exact values?
using System.Text.Json;
public class Car
{
public int Year { get; set; } // does serialize correctly
public string Model; // doesn't serialize correctly
}
static void Problem() {
Car car = new Car()
{
Model = "Fit",
Year = 2008,
};
string json = JsonSerializer.Serialize(car); // {"Year":2008}
Car carDeserialized = JsonSerializer.Deserialize<Car>(json);
Console.WriteLine(carDeserialized.Model); // null!
}
In .NET Core 3.x, System.Text.Json does not serialize fields. From the docs:
Fields are not supported in System.Text.Json in .NET Core 3.1. Custom converters can provide this functionality.
In .NET 5 and later, public fields can be serialized by setting JsonSerializerOptions.IncludeFields to true or by marking the field to serialize with [JsonInclude]:
using System.Text.Json;
static void Main()
{
var car = new Car { Model = "Fit", Year = 2008 };
// Enable support
var options = new JsonSerializerOptions { IncludeFields = true };
// Pass "options"
var json = JsonSerializer.Serialize(car, options);
// Pass "options"
var carDeserialized = JsonSerializer.Deserialize<Car>(json, options);
Console.WriteLine(carDeserialized.Model); // Writes "Fit"
}
public class Car
{
public int Year { get; set; }
public string Model;
}
For details see:
How to serialize and deserialize (marshal and unmarshal) JSON in .NET: Include fields.
Issues #34558 and #876.
If you want this for all MvcControllers in API project you can do similar to this in setup:
builder.Services.AddControllers().AddJsonOptions(options =>
{
options.JsonSerializerOptions.IncludeFields = true;
});
Please try this library I wrote as an extension to System.Text.Json to offer missing features: https://github.com/dahomey-technologies/Dahomey.Json.
You will find support for fields.
using System.Text.Json;
using Dahomey.Json
public class Car
{
public int Year { get; set; } // does serialize correctly
public string Model; // will serialize correctly
}
static void Problem() {
JsonSerializerOptions options = new JsonSerializerOptions();
options.SetupExtensions(); // extension method to setup Dahomey.Json extensions
Car car = new Car()
{
Model = "Fit",
Year = 2008,
};
string json = JsonSerializer.Serialize(car, options); // {"Year":2008,"Model":"Fit"}
Car carDeserialized = JsonSerializer.Deserialize<Car>(json);
Console.WriteLine(carDeserialized.Model); // Fit
}

Deserialize Web Api OData response

I have an Entity Framework object returned by OData V4 controller.
I return an IQueryable and if I call the OData endpoint without any OData clause I can succesfully do this:
var content = response.Content.ReadAsAsync<IQueryable<Person>>();
And the response in JSON is the following:
{
"#odata.context":"http://xxx:8082/odata/$metadata#Persons","value":[
{
"Id":"291b9f1c-2587-4a35-993e-00033a81f6d5",
"Active":true,
"Alert":"Some alerts for the Person",
"Comments":"Some comments for the Person"
}
]
}
But as soon as I start to play with OData, for example by using $expand on a Complex property I get the following exception:
Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Linq.IQueryable`1[xxx.Person]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.
And the response is the following:
{
"#odata.context":"http://aqavnext01:8082/odata/$metadata#Persons","value":[
{
"Id":"291b9f1c-2587-4a35-993e-00033a81f6d5",
"Active":true,
"Alert":"Some alerts for the Person",
"Comments":"Some comments for the Person",
"Party":{
"Id":"291b9f1c-2587-4a35-993e-00033a81f6d5"
}
}
]
}
And I am deserializing using the same object returned by my Web Api so I don't understand why it fails.
Same issue when I apply $select.
Try deserialize the content like this:
var content = response.Content.ReadAsAsync<ODataResponse<Person>>();
Where ODataResponse is:
internal class ODataResponse<T>
{
public T[] Value { get; set; }
}
If you need access to the #odata.xxx fields in the response JSON (such as implementing a loop for paged results), the following is my implementation which expands on the solution from andygjp.
I'm using RestSharp as my HTTP client and Json.NET for (de)serialization. Steps as follows.
Implement a custom IRestSerializer that uses Json.NET to replace the default RestSharp serializer. Below example implementation:
public class JsonNetSerializer : IRestSerializer
{
private readonly JsonSerializerSettings _settings;
public JsonNetSerializer()
{
_settings = new JsonSerializerSettings
{
NullValueHandling = NullValueHandling.Ignore
};
_settings.Converters.Add(new StringEnumConverter());
}
public string Serialize(Parameter parameter) => JsonConvert.SerializeObject(parameter.Value, Formatting.None, _settings);
public string Serialize(object obj) => JsonConvert.SerializeObject(obj, Formatting.None, _settings);
public T Deserialize<T>(IRestResponse response) => JsonConvert.DeserializeObject<T>(response.Content);
public string[] SupportedContentTypes => new string[] { "application/json", "text/json", "text/x-json", "text/javascript", "*+json" };
public DataFormat DataFormat => DataFormat.Json;
public string ContentType { get; set; } = "application/json";
}
Next, define a class that will represent your OData responses. My expanded response class - which includes the #odata.nextLink field - looks as follows.
private class ODataResponse<T>
{
public T[] Value { get; set; }
[JsonProperty("#odata.nextLink")]
public string NextLink { get; set; }
}
Finally, I create an instance of RestClient, setting up the custom serializer previously created:
var client = new RestClient("https://base.url.here/")
.UseSerializer(() => new JsonNetSerializer());
Now when I execute my request, the data in the response object object also contains my OData values.
var response = await client.ExecuteAsync<T>(request);
var nextLink = response.Data.NextLink;
I'm sure this can be done using the standard HttpClient instead of RestSharp, as the real work is done by the serializer. This was just the example implementation I had on hand.

How to extract data from JSON in ASP.NET using c#

{"pometek.net":{"status":"available","classkey":"dotnet"},"pometek.com":{"status":"available","classkey":"domcno"}}
I want to dispense this in table format. Need help.
You can use Json.NET to deserialize the json object into a C# class, and then map that class to a table format in asp.net
You shouldn't need a third-party library; the out-of-the-box JavaScriptSerializer can handle this.
class Item {
public string status { get; set; }
public string classkey { get; set; }
}
var jss = new System.Web.Script.Serialization.JavaScriptSerializer();
var input = "{\"pometek.net\":{\"status\":\"available\",\"classkey\":\"dotnet\"},\"pometek.com\":{\"status\":\"available\",\"classkey\":\"domcno\"}}";
var results = jss.Deserialize<Dictionary<string, Item>(input);
var query = results["pometek.net"].status; // = "available"
Displaying this as a table is a separate step.

How to ignore a property in class if null, using json.net

I am using Json.NET to serialize a class to JSON.
I have the class like this:
class Test1
{
[JsonProperty("id")]
public string ID { get; set; }
[JsonProperty("label")]
public string Label { get; set; }
[JsonProperty("url")]
public string URL { get; set; }
[JsonProperty("item")]
public List<Test2> Test2List { get; set; }
}
I want to add a JsonIgnore() attribute to Test2List property only when Test2List is null. If it is not null then I want to include it in my json.
An alternate solution using the JsonProperty attribute:
[JsonProperty(NullValueHandling=NullValueHandling.Ignore)]
// or
[JsonProperty("property_name", NullValueHandling=NullValueHandling.Ignore)]
// or for all properties in a class
[JsonObject(ItemNullValueHandling = NullValueHandling.Ignore)]
As seen in this online doc.
As per James Newton King: If you create the serializer yourself rather than using JavaScriptConvert there is a NullValueHandling property which you can set to ignore.
Here's a sample:
JsonSerializer _jsonWriter = new JsonSerializer {
NullValueHandling = NullValueHandling.Ignore
};
Alternatively, as suggested by #amit
JsonConvert.SerializeObject(myObject,
Newtonsoft.Json.Formatting.None,
new JsonSerializerSettings {
NullValueHandling = NullValueHandling.Ignore
});
JSON.NET also respects the EmitDefaultValue property on DataMemberAttribute, in case you don't want to add Newtonsoft-specific attributes to your model:
[DataMember(Name="property_name", EmitDefaultValue=false)]
You can write: [JsonProperty("property_name",DefaultValueHandling = DefaultValueHandling.Ignore)]
It also takes care of not serializing properties with default values (not only null). It can be useful for enums for example.
You can do this to ignore all nulls in an object you're serializing, and any null properties won't then appear in the JSON
JsonSerializerSettings settings = new JsonSerializerSettings();
settings.NullValueHandling = NullValueHandling.Ignore;
var myJson = JsonConvert.SerializeObject(myObject, settings);
In my case, using .NET 6 this was the solution:
[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
More info here.
As can be seen in this link on their site (http://james.newtonking.com/archive/2009/10/23/efficient-json-with-json-net-reducing-serialized-json-size.aspx) I support using [Default()] to specify default values
Taken from the link
public class Invoice
{
public string Company { get; set; }
public decimal Amount { get; set; }
// false is default value of bool
public bool Paid { get; set; }
// null is default value of nullable
public DateTime? PaidDate { get; set; }
// customize default values
[DefaultValue(30)]
public int FollowUpDays { get; set; }
[DefaultValue("")]
public string FollowUpEmailAddress { get; set; }
}
Invoice invoice = new Invoice
{
Company = "Acme Ltd.",
Amount = 50.0m,
Paid = false,
FollowUpDays = 30,
FollowUpEmailAddress = string.Empty,
PaidDate = null
};
string included = JsonConvert.SerializeObject(invoice,
Formatting.Indented,
new JsonSerializerSettings { });
// {
// "Company": "Acme Ltd.",
// "Amount": 50.0,
// "Paid": false,
// "PaidDate": null,
// "FollowUpDays": 30,
// "FollowUpEmailAddress": ""
// }
string ignored = JsonConvert.SerializeObject(invoice,
Formatting.Indented,
new JsonSerializerSettings { DefaultValueHandling = DefaultValueHandling.Ignore });
// {
// "Company": "Acme Ltd.",
// "Amount": 50.0
// }
In .Net Core this is much easier now. In your startup.cs just add json options and you can configure the settings there.
public void ConfigureServices(IServiceCollection services)
....
services.AddMvc().AddJsonOptions(options =>
{
options.SerializerSettings.NullValueHandling = NullValueHandling.Ignore;
});
With Json.NET
public class Movie
{
public string Name { get; set; }
public string Description { get; set; }
public string Classification { get; set; }
public string Studio { get; set; }
public DateTime? ReleaseDate { get; set; }
public List<string> ReleaseCountries { get; set; }
}
Movie movie = new Movie();
movie.Name = "Bad Boys III";
movie.Description = "It's no Bad Boys";
string ignored = JsonConvert.SerializeObject(movie,
Formatting.Indented,
new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
The result will be:
{
"Name": "Bad Boys III",
"Description": "It's no Bad Boys"
}
With System.Text.Json and .NET Core 3.0 this worked for me:
var jsonSerializerOptions = new JsonSerializerOptions()
{
IgnoreNullValues = true
};
var myJson = JsonSerializer.Serialize(myObject, jsonSerializerOptions );
An adaption to #Mrchief's / #amit's answer, but for people using VB
Dim JSONOut As String = JsonConvert.SerializeObject(
myContainerObject,
New JsonSerializerSettings With {
.NullValueHandling = NullValueHandling.Ignore
}
)
See:
"Object Initializers: Named and Anonymous Types (Visual Basic)"
https://msdn.microsoft.com/en-us/library/bb385125.aspx
Or just by setting like this.
services.AddMvc().AddJsonOptions(options =>
options.JsonSerializerOptions.IgnoreNullValues = true;
});
To expound slightly on GlennG's very helpful answer (translating the syntax from C# to VB.Net is not always "obvious") you can also decorate individual class properties to manage how null values are handled. If you do this don't use the global JsonSerializerSettings from GlennG's suggestion, otherwise it will override the individual decorations. This comes in handy if you want a null item to appear in the JSON so the consumer doesn't have to do any special handling. If, for example, the consumer needs to know an array of optional items is normally available, but is currently empty...
The decoration in the property declaration looks like this:
<JsonPropertyAttribute("MyProperty", DefaultValueHandling:=NullValueHandling.Include)> Public Property MyProperty As New List(of String)
For those properties you don't want to have appear at all in the JSON change :=NullValueHandling.Include to :=NullValueHandling.Ignore.
By the way - I've found that you can decorate a property for both XML and JSON serialization just fine (just put them right next to each other). This gives me the option to call the XML serializer in dotnet or the NewtonSoft serializer at will - both work side-by-side and my customers have the option to work with XML or JSON. This is slick as snot on a doorknob since I have customers that require both!
Here's an option that's similar, but provides another choice:
public class DefaultJsonSerializer : JsonSerializerSettings
{
public DefaultJsonSerializer()
{
NullValueHandling = NullValueHandling.Ignore;
}
}
Then, I use it like this:
JsonConvert.SerializeObject(postObj, new DefaultJsonSerializer());
The difference here is that:
Reduces repeated code by instantiating and configuring JsonSerializerSettings each place it's used.
Saves time in configuring every property of every object to be serialized.
Still gives other developers flexibility in serialization options, rather than having the property explicitly specified on a reusable object.
My use-case is that the code is a 3rd party library and I don't want to force serialization options on developers who would want to reuse my classes.
Potential drawbacks are that it's another object that other developers would need to know about, or if your application is small and this approach wouldn't matter for a single serialization.
This does not exactly answer the original question, but may prove useful depending on the use case. (And since I wound up here after my search, it may be useful for others.)
In my most recent experience, I'm working with a PATCH api. If a property is specified but with no value given (null/undefined because it's js), then the property and value are removed from the object being patched. So I was looking for a way to selectively build an object that could be serialized in such a way that this would work.
I remembered seeing the ExpandoObject, but never had a true use case for it until today. This allows you to build an object dynamically, so you won't have null properties unless you want them there.
Here is a working fiddle, with the code below.
Results:
Standard class serialization
noName: {"Name":null,"Company":"Acme"}
noCompany: {"Name":"Fred Foo","Company":null}
defaultEmpty: {"Name":null,"Company":null}
ExpandoObject serialization
noName: {"Company":"Acme"}
noCompany: {"name":"Fred Foo"}
defaultEmpty: {}
Code:
using Newtonsoft.Json;
using System;
using System.Dynamic;
public class Program
{
public static void Main()
{
SampleObject noName = new SampleObject() { Company = "Acme" };
SampleObject noCompany = new SampleObject() { Name = "Fred Foo" };
SampleObject defaultEmpty = new SampleObject();
Console.WriteLine("Standard class serialization");
Console.WriteLine($" noName: { JsonConvert.SerializeObject(noName) }");
Console.WriteLine($" noCompany: { JsonConvert.SerializeObject(noCompany) }");
Console.WriteLine($" defaultEmpty: { JsonConvert.SerializeObject(defaultEmpty) }");
Console.WriteLine("ExpandoObject serialization");
Console.WriteLine($" noName: { JsonConvert.SerializeObject(noName.CreateDynamicForPatch()) }");
Console.WriteLine($" noCompany: { JsonConvert.SerializeObject(noCompany.CreateDynamicForPatch()) }");
Console.WriteLine($" defaultEmpty: { JsonConvert.SerializeObject(defaultEmpty.CreateDynamicForPatch()) }");
}
}
public class SampleObject {
public string Name { get; set; }
public string Company { get; set; }
public object CreateDynamicForPatch()
{
dynamic x = new ExpandoObject();
if (!string.IsNullOrWhiteSpace(Name))
{
x.name = Name;
}
if (!string.IsNullOrEmpty(Company))
{
x.Company = Company;
}
return x;
}
}
.Net 6 -
Add the code in Program.cs. This will ignore the class or record property if it is null.
using System.Text.Json.Serialization;
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddControllers()
.AddJsonOptions(opts =>
{
var enumConverter = new JsonStringEnumConverter();
opts.JsonSerializerOptions.Converters.Add(enumConverter);
opts.JsonSerializerOptions.DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingDefault | JsonIgnoreCondition.WhenWritingNull;
});
var settings = new JsonSerializerSettings();
settings.ContractResolver = new CamelCasePropertyNamesContractResolver();
settings.NullValueHandling = NullValueHandling.Ignore;
//you can add multiple settings and then use it
var bodyAsJson = JsonConvert.SerializeObject(body, Formatting.Indented, settings);

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